Truthfully, FDR messed up many times and acutally made the economy worse. There were policies like giving people seed to plant when the drought was on, and they just died. He supported Dixiecrats which threw people off of the sharecropper homes they lived in, and busted up unions, despite simultaneously supporting unions elsewhere.The programs of the New Deal were fraught with abuse.

In all honesty it was only when we began selling arms to Britain and then entering the war and regearing up the factories that there was an improvement in the economy.